A new study of Chinese women indicates the benefits of healthy lifestyle choices can really add up.

Diet and exercise can have a big impact on health. The scientific literature is full of studies about the effect of various lifestyle factors, but relatively few studies look at the combined influence of multiple factors, and almost all of them were done in Western countries.

Now, a large study of women in Shanghai has found a strong association between a healthy lifestyle in general and a lower death rate, over an average of nine years.

The research considered factors such as obesity and exposure to second-hand smoke.

"We found that those people with a very healthy lifestyle, they have about 40 percent reduction in total mortality, and about 70 percent reduction in cardiovascular disease mortality, and about 25 percent reduction in cancer mortality," said Dr. Wei Zheng of Vanderbilt University. He is the lead author of the new study, which also included researchers from the Shanghai Cancer Institute and America's National Cancer Institute.

In this study, some 75,000 Chinese women were each given a healthy lifestyle score based on body mass index, waist-hip ratio, exercise, diet, and whether her husband smoked. The women were non-smokers and did not drink alcohol regularly.

Zheng says this study differs in several ways from other lifestyle research.

"This is one of the few studies that looks at the overall impact of multiple risk factors. Most of the previous studies look at smoking, drinking excessively. This is one of the few studies that just looks at combined lifestyle factors on mortality among those who never smoked cigarettes and who do not drink regularly."

It's also among the first studies of its kind conducted in a non-Western country.

Zheng says the research suggests that a longer and healthier life is not achieved by just a better diet or more exercise or other single lifestyle factor alone.

"So the message from this study is that we need to encourage general modification of multiple lifestyle factors for disease prevention."

Wei Zheng's study on lifestyle and mortality is published in the open-access journal PloS Medicine.